Valve arrangement for a medical apparatus

Abstract

A valve arrangement for stopping fluid passage through at least one flexible tubing is provided with a camshaft having at least one control cam which is designed as a sink in an otherwise closed circular surface of the camshaft for moving a press member which is retracted into an inactive relative position when radially aligned with the sink and which is protruded into an active relative position by the circular surface of the camshaft for then squeezing the associated portion of the flexible tube which is passed through a housing of the valve arrangement in a direction normal with respect to a longitudinal bore rotatably supporting the camshaft and also normal with respect to a radial bore which is arranged for radially guiding the press member.

We claim:  
     
       1. A valve arrangement for a medical apparatus for stopping fluid passage through a flexible tubing, comprising: 
       a valve housing through which a portion of the flexible tubing is passed,  
       a camshaft which is rotatably supported in a longitudinal bore of the valve housing and which has at least one control cam for moving and guiding at least one press member in a first radial bore which extends in a radial direction with respect to a longitudinal bore, the press member being moved between a retracted inactive relative position and a protruded active relative position in which the associated portion of the flexible tubing is squeezed by the press member for stopping fluid passage through the flexible tubing;  
       said portion of the flexible tubing passing through the valve housing extends in a direction normal with respect to the longitudinal bore rotatably supporting the camshaft and also normal with respect to the radial bore which is arranged for guiding said at least one press member,  
       said at least one control cam is formed by a first sink of the otherwise closed circular surface of the camshaft which when being radially aligned with said at least one press member determines a retracted inactive relative position of the press member the corresponding protruded active relative position of which is obtained with the closed circular surface of the camshaft which is contacted by the press member while the camshaft is rotated.  
     
     
       2. The valve arrangement according to  claim 1 , wherein the camshaft has at least a second control cam for moving and guiding at least a second press member in a second radial bore of the valve housing at a position in which a portion of at least a second flexible tubing is passed through the valve housing, said at least second control cam being formed by a second sink which is axially offset from said first sink on the otherwise closed circular surface of the camshaft at a circumferential position of a different central angle than said first sink. 
     
     
       3. The valve arrangement according to  claim 2 , wherein said first and second sinks which are axially and circumferentially offset with respect to each other determine the timing for stopping fluid passage through the one flexible tubing and the at least second flexible tubing alternately by said at least one and second press members in their protruded active relative position for squeezing an adjacent portion of a flexible tubing in two different turning positions of the camshaft. 
     
     
       4. The valve arrangement according to  claim 3 , wherein the one and the at least second flexible tubings are connected downstream of the valve arrangement with a common connecting line by which the fluids which are carried by these flexible tubings upstream of the valve arrangement are alternately supplied to an interconnected medical apparatus. 
     
     
       5. The valve arrangement according to  claim 1 , wherein the camshaft may be turned into a first neutral control position in which said at least one press member is arranged in its protruded active relative position. 
     
     
       6. The valve arrangement according to  claim 1 , wherein the camshaft may be turned into a second neutral control position in which a microswitch is actuated by a switch lever that is operatively coupled with the camshaft for switching on and off a pump which is provided for feeding the fluid. 
     
     
       7. The valve arrangement according to  claim 1 , wherein the camshaft may be manually turned by a turning handle which is provided on a medical apparatus in which the valve arrangement is housed. 
     
     
       8. The valve arrangement according to  claim 1 , wherein the camshaft may be turned by a step motor. 
     
     
       9. The valve arrangement according to  claim 1 , wherein at least a further control cam of the camshaft is arranged for allowing a mass flow control of the fluid passing through an associated portion of a flexible tubing. 
     
     
       10. The valve arrangement according to  claim 9 , wherein a sink forming the further control cam of the camshaft for allowing a mass flow control of the fluid is less shallow than a sink by which fluid passage through a flexible tubing is controlled.